“What do you mean by the centre of gravity?” inquired Marcus.
“Why, the point where the weight of the whole thing is evenly balanced,” said Ronald; “for instance, if I balance this book on the end of my finger, the point that rests on my finger will be the centre of gravity.”
“Yes, you have the idea,” resumed Marcus; “and this little experiment is explained on the same principle. The weight of the forks, projecting as they do so much below the coin, brings the centre of gravity of the arrangement below the point of the needle, which is the point of suspension; and the coin is much less liable to fall off than it would be if the centre of gravity were higher.”
“Now let me show you a little experiment,” said Ronald. “I’m going to put two chairs back to back, take off my shoes, and jump over them. Do you believe I can do it?”
“This isn’t a suitable place for such rough play—if you want to do any jumping, you had better go out-doors,” said Mrs. Page.
“But I wont do the least harm in the world,” replied Ronald. “Let me show you how I do it, wont you?”
Mrs. Page making no reply, Ronald inferred that she consented; and placing the chairs as he had described, he took off his shoes, and drawing back to the end of the room, ran and jumped over the—shoes, to the great amusement of those who were watching the “experiment.”
Marcus and Oscar had resumed their reading, and Ronald and Otis now began to amuse themselves with a puzzle which they called the Moslem Oracle. It was a table, divided by lines into a hundred little squares, in each of which was written a letter, as follows:
| d | w | w | a | w | o | h | a | b | h |
| i | o | i | s | o | t | d | t | t | w |
| w | o | a | a | a | i | e | n | i | i |
| t | s | d | n | t | h | i | a | a | e |
| o | t | t | n | t | u | w | t | d | h |
| t | i | a | e | s | f | l | i | n | u |
| e | l | n | j | c | a | d | t | o | c |
| r | o | h | y | e | o | w | y | p | e |
| f | r | w | e | d | i | o | i | a | e |
| l | n | s | c | t | l | g | h | e | h |
The boy from whom they obtained a copy of this Oracle, told them he had read that it was sometimes actually used by the superstitious Moslems, when they were in doubt about any thing they thought of doing. The rule is to repeat certain verses of the Koran, and then to place the finger upon the table, without looking at it. The Moslem then looks to see on what letter his finger has rested, and writes it down, with every fifth following letter in the table, until he has got back to his starting place. For example, we will suppose his finger fell on the letter e in the sixth line. He writes down every fifth letter, and the following appears: